The fact that the solid state light source is a small light source presents opportunities as well as challenges. On the one hand the small size of the solid state light source allows for lamps having a compacter design, but on the other hand it is challenging to obtain efficient light distribution from such lamps. It is further challenging to avoid the light emitted from the solid state light source to appear as high brightness spots in the lamp.
Hence, there is a need for solid state based lamps that are able to provide efficient uniform illumination.